Yabasic (Yet Another BASIC) is a free and open source BASIC interpreter for Windows and Unix platforms. Yabasic was originally developed by Marc-Oliver Ihm, who released the last stable version 2.769 in 2015. As a continuation of the project, version 3 is now developed by a team centered on Pedro Sá and Thomas Larsen.
A port of Yabasic to the Fltk toolkit called "Flyab" was under development. It would have been source-compatible with programs written in yab, a variant of Yabasic that enables graphical programs to be written using the BeOS API. Ports for Windows, Mac OS X, and Linux were planned. Flyab added the ability to Yabasic to create native graphical user interfaces on all supported platforms. As of November 2008, the project appears to be halted.